Trouble Symptom Chart
CAUTION:
During troubleshooting, a DTC associated with another system may be set when the ignition switch is turned on with connector(s) disconnected. On completion, confirm all systems for DTC(s). If DTC(s) are set, erase them all.
| Trouble symptom | Inspection procedure | Reference or action |
|---|---|---|
| Scan tool cannot communicate with electric power steering system < ECU power supply circuit system check >. | 1 | INSPECTION PROCEDURE 1: SCAN TOOL CANNOT COMMUNICATE WITH ELECTRIC POWER STEERING SYSTEM < ECU POWER SUPPLY CIRCUIT SYSTEM CHECK >. |
| Electric power steering system warning display illuminates but diagnostic trouble code is not stored. | 2 | INSPECTION PROCEDURE 2: ELECTRIC POWER STEERING SYSTEM WARNING DISPLAY ILLUMINATES BUT DIAGNOSTIC TROUBLE CODE IS NOT STORED. |
| The steering has become heavy, but the electric power steering warning display does not illuminate (This is normal, because the electric power steering is limiting assist operation).
NOTE:
If the vehicle is driven under heavy load (e.g. consecutively turning the steering to full lock or severe cornering), the electric power steering motor drive circuit will become hot. In this case, the electric power steering system will limit assist operation by decreasing the motor current to avoid damage. In this case, the steering will become heavy, but the electric power steering warning lamp does not illuminate. If the circuit temperature reduces after a while, the assist operation will return to the normal level.
|
- | Reproduce the steering operation, which your customer did. Check the M.U.T.-III data list item to No.A55 from No.A11, and confirm that the electric power steering system limited the assist operation (Refer to DATA LIST REFERENCE TABLE ). Note that this is not a failure. |
| The steering has become heavy, but the electric power steering warning display does not illuminate (Power supply voltage assist fall).
NOTE:
If the system voltage is lower than the rated value, motor rated output does not come out.
|
3 | INSPECTION PROCEDURE 3: THE STEERING HAS BECOME HEAVY, BUT ELECTRIC POWER STEERING WARNING DISPLAY DOES NOT ILLUMINATE. (POWER SUPPLY VOLTAGE ASSIST FALL) |